Technical aspects

Construction

See also: Motorcycle components and Motorcycle design

Motorcycle construction is the engineering, manufacturing, and assembly of components and systems for a motorcycle which results in the performance, cost, and aesthetics desired by the designer. With some exceptions, construction of modern mass-produced motorcycles has standardised on a steel or aluminium frame, telescopic forks holding the front wheel, and disc brakes. Some other body parts, designed for either aesthetic or performance reasons may be added. A petrol powered engine typically consisting of between one and four cylinders (and less commonly, up to eight cylinders) coupled to a manual five- or six-speed sequential transmission drives the swingarm-mounted rear wheel by a chain, driveshaft or belt.

Fuel economy

Motorcycle fuel economy varies greatly with engine displacement and riding style ranging from a low of 29 mpg-US (8.1 L/100 km; 35 mpg-imp) reported by a Honda VTR1000F rider, to 107 mpg-US (2.2 L/100 km; 129 mpg-imp) reported for the Verucci Nitro 50 cc scooter. A specially designed Matzu Matsuzawa Honda XL125 achieved 470 mpg-US (0.50 L/100 km; 560 mpg-imp) "on real highways – in real conditions." Due to low engine displacements (100 cc–200 cc), and high power-to-mass ratios, motorcycles offer good fuel economy. Under conditions of fuel scarcity like 1950s Britain and modern developing nations, motorcycles claim large shares of the vehicle market.

Electric motorcycles

Main article: Electric motorcycle

Very high fuel economy equivalents are often derived by electric motorcycles. Electric motorcycles are nearly silent, zero-emission electric motor-driven vehicles. Operating range and top speed are limited by battery technology.[citation needed] Fuel cells and petroleum-electric hybrids are also under development to extend the range and improve performance of the electric drive system.

Reliability

A 2013 survey of 4,424 readers of the US Consumer Reports magazine collected reliability data on 4,680 motorcycles purchased new from 2009 to 2012. The most common problem areas were accessories, brakes, electrical (including starters, charging, ignition), and fuel systems, and the types of motorcycles with the greatest problems were touring, off road/dual sport, sport-touring, and cruisers. There were not enough sport bikes in the survey for a statistically significant conclusion, though the data hinted at reliability as good as cruisers. These results may be partially explained by accessories including such equipment as fairings, luggage, and auxiliary lighting, which are frequently added to touring, adventure touring/dual sport and sport touring bikes. Trouble with fuel systems is often the result of improper winter storage, and brake problems may also be due to poor maintenance.

 Of the five brands with enough data to draw conclusions, Honda, Kawasaki and Yamaha were statistically tied, with 11 to 14% of those bikes in the survey experiencing major repairs. Harley-Davidsons had a rate of 24%, while BMWs did worst, with 30% of those needing major repairs. There were not enough Triumph and Suzuki motorcycles surveyed for a statistically sound conclusion, though it appeared Suzukis were as reliable as the other three Japanese brands while Triumphs were comparable to Harley-Davidson and BMW. Three fourths of the repairs in the survey cost less than US$ 200 and two thirds of the motorcycles were repaired in less than two days. In spite of their relatively worse reliability in this survey, Harley-Davidson and BMW owners showed the greatest owner satisfaction, and three fourths of them said they would buy the same bike again, followed by 72% of Honda owners and 60 to 63% of Kawasaki and Yamaha owners.

Dynamics

Racing motorcycles leaning in a turn.

Main article: Bicycle and motorcycle dynamics

Different types of motorcycles have different dynamics and these play a role in how a motorcycle performs in given conditions. For example, one with a longer wheelbase provides the feeling of more stability by responding less to disturbances. Motorcycle tyres have a large influence over handling.

Motorcycles must be leaned in order to make turns. This lean is induced by the method known as countersteering, in which the rider momentarily steers the handlebars in the direction opposite of the desired turn. This practice is counter-intuitive and therefore often confusing to novices – and even many experienced motorcyclists.

Such short wheelbase motorcycles as sport bikes can generate enough torque at the rear wheel, and enough stopping force at the front wheel, to lift the opposite wheel off the road. These actions, if performed on purpose, are known as wheelies and stoppies respectively. If carried past the point of recovery the resulting upset is known as an "endo" (short for "end-over-end"), or "looping" the vehicle.

Accessories

Main article: Motorcycle accessories

Various features and accessories may be attached to a motorcycle either as OEM (factory-fitted) or after-market. Such accessories are selected by the owner to enhance the motorcycle's appearance, safety, performance, or comfort, and may include anything from mobile electronics to sidecars and trailers.